The Tennis Court Oath was a pivotal moment during the French Revolution. It occurred on June 20, 1789, when members of the French Third Estate gathered in a tennis court at the Palace of Versailles. Here are the details of the oath:

The cause of the oath
- The French Third Estate was made up of commoners, who were seeking political and social reforms that would benefit them.
- They were frustrated with the way the Estates-General was being conducted, and believed that the First and Second Estates (made up of clergy and nobility, respectively) were not taking their concerns seriously.
- The Third Estate demanded that the Estates-General be reformed so that each member had equal representation, rather than being dominated by the First and Second Estates.

The events leading up to the oath
- On June 17, 1789, the Third Estate declared itself to be the National Assembly, and invited members of the other two Estates to join them.
- On June 19, the National Assembly was locked out of their meeting place, the Salle des États, so they convened in a nearby tennis court instead.

The oath itself
- The members of the National Assembly swore an oath not to disband until they had created a new constitution for France.
- The oath was led by Jean-Sylvain Bailly, the president of the National Assembly, and was taken by approximately 576 members.
- The oath became known as the Tennis Court Oath, and was seen as a symbol of the Third Estate's determination to achieve political reform.

The significance of the oath
- The Tennis Court Oath was a significant moment in the French Revolution, as it demonstrated the strength and unity of the Third Estate.
- It also showed that the members of the National Assembly were willing to take bold actions to achieve their goals.
- The oath ultimately led to the drafting of the Declaration of the Rights of Man and Citizen, which established the principles of liberty, equality, and fraternity in France.

On 20 June 1789, the members of the French Third Estate took the Tennis Court Oath(French: Serment du Jeu de Paume), vowing "not to separate, and to reassemble wherever circumstances require, until the constitution of the kingdom is established". It was a pivotal event in the French Revolution. The Estates-General had been called to address the country's fiscal and agricultural crisis, but they had become bogged down in issues of representation immediately after convening in May 1789, particularly whether they would vote by order or by head (which would increase the power of the Third Estate, as they outnumbered the other two estates hugely).

On 17 June, the Third Estate began to call themselves the National Assembly, led by the Honoré Gabriel Riqueti, Comte de Mirabeau.[1]On the morning of 20 June, the deputies were shocked to discover that the chamber door was locked and guarded by soldiers. They immediately feared the worst and were anxious that a royal attack was imminent from King Louis XVI, so the deputies congregated in a nearby indoor jeu de paumecourt [fr] in the Saint-Louis district [fr] of the city of Versailles near the Palace of Versailles. There 576 of the 577 members from the Third Estate took a collective oath "not to separate, and to reassemble wherever circumstances require, until the constitution of the kingdom is established".[2] The only person who did not join was Joseph Martin-Dauch from Castelnaudary, who would only execute decisions that were made by the king.[3]